Method for manufacturing a pants-type disposable absorbent hygience article

ABSTRACT

The invention relates to a method for manufacturing a pant-type disposable absorbent hygiene article ( 2 ), comprising a waist edge ( 20 ), sealed all around the periphery thereof, forming a waist opening and with leg openings ( 8 ), wherein longitudinal side edge sections ( 16 ),  18 ) of a front piece ( 6 ) and a back piece ( 4 ) are joined together by the manufacturer to form the waist edge ( 20 ), sealed all around the periphery thereof and the leg openings ( 8 ), and having an absorbent body ( 22 ) and elasticizing means ( 38 ) at least in the region of the leg openings ( 8 ). The aim of the invention is to improve the wearing comfort. This aim is achieved, in that, before the longitudinal side edge sections ( 16, 18 ) are joined together by the manufacturer, the hygiene article, when laid flat, is provided with a first elasticised periphery section ( 44 ), followed by a second non-elasticized periphery section ( 46 ), followed by a third elasticized periphery section ( 48 ) and followed by a fourth non-elasticized periphery section ( 49 ), extending from a longitudinal side edge ( 12, 14 ) of the front piece ( 6 ) or back piece ( 4 ) of the article, towards a crotch center line ( 42 ), along a periphery ( 40 ) of a corresponding leg opening ( 8 ).

This application is a continuation of Ser. No. 11/628,467 filed Dec. 4,2006 as the national stage of PCT/EP2005/006235 filed on Jun. 10, 2005and also claims Paris Convention priority of DE 10 2004 032 377.1 filedon Jun. 29, 2004, the entire disclosures of which are herebyincorporated by reference.

BACKGROUND OF THE INVENTION

The invention concerns a method for producing a pants-type disposableabsorbent hygiene article with a hip edge which is continuously closedin the peripheral direction and forms a hip opening, and with legopenings, wherein the hip edge which is continuously closed in theperipheral direction and the leg openings are formed by connectinglongitudinal side edge sections of a front part and rear part to eachother at the manufacturing plant, and having an absorbent body andelasticizing means at least in the area of the leg openings.

Conventional pants-type absorbent hygiene articles of this type usuallycomprise a plurality of elasticizing means, often in the form ofrubber-elastic threads which are mostly glued to chassis materials inthe pretensioned state. A hip edge area is thereby usually preferablycontinuously elasticized in the peripheral direction. Conventionalpants-type diapers also have elasticizing means in the front and rearareas. The peripheral areas forming or surrounding the leg openings arealso continuously elasticized to ensure tight fit of the hygiene articleon the skin surface of the user in order to prevent lateral escape ofbody excretions.

Abutment of pretensioned, elasticized areas on the skin surfaceespecially in the area of the leg openings can cause skin irritationsdue to friction or force exerted by the mostly thread-shapedelasticizing means. This problem is aggravated by the presence ofadditional moisture within the hygiene article due to body liquids orperspiration and is aggravated by increasing activity, i.e. movement ofthe user.

Departing therefrom, it is the underlying purpose of the presentinvention to provide a method for manufacturing a pants-type hygienearticle of the above-mentioned kind having improved wearing comfort and,in particular, reduced skin irritation.

SUMMARY OF THE INVENTION

This object is achieved in accordance with the invention with a methodfor manufacturing a hygiene article of this type as recited in theindependent claim.

In particular, the manufactured hygiene article has a first elasticizingperipheral section, adjacent thereto, a second non-elasticizingperipheral section, adjacent thereto, a third elasticizing peripheralsection, and adjacent thereto, a fourth non-elasticizing peripheralsection are provided in the flat state before connecting thelongitudinal side edge sections at the manufacturing plant, extendingfrom a longitudinal side edge of the front part or rear part of thearticle along the periphery of a respective leg opening towards a centercrotch line.

In accordance with the invention, it is not necessary to elasticise theentire leg opening of a pants-type diaper. In view of the fact thatmodern hygiene articles have additional upright collar elements,so-called “cuff elements”, which extend substantially in thelongitudinal direction and which form a lateral barrier for escapingliquid and solid body excretions, leg openings which are continuouslyelasticized in the peripheral direction no longer appear to beabsolutely necessary. Since the elasticizing means gather or frill thematerial to which they are connected in the pretensioned state, theyaccumulate material in the relaxed state which may be uncomfortable e.g.during sitting. In any event, gathered or frilled areas, i.e.elasticized areas, severely rub the skin surface of the user, inparticular while he/she is moving, which can cause the above-mentionedskin irritation. It has turned out in accordance with the invention thatthis can be counteracted by only using elasticizing means in the crotcharea at locations where they are actually required. In accordance withthe invention, the wearing comfort is improved in that a secondnon-elasticized peripheral section is disposed between the firstperipheral section facing the hip area and the third peripheral sectiondisposed between the legs of the user, and a further non-elasticizedfourth peripheral section is provided in the area of a center crotchline. The respective material sections of the second and fourthperipheral section of the hygiene article abut the skin surface of theuser with slight pretension. Since the second peripheral section is notsubjected to permanently changing gathering or frilling, it does not rubon the surface of the skin. Moreover, air exchange with the inside ofthe hygiene article is possible, which considerably improves themicroclimate in the areas of the skin surface covered by the hygienearticle.

An improvement in accordance with the invention is already achieved byproviding such a non-elasticized second peripheral section only alongthe peripheral area of the two leg openings facing the front part. In afurther development of this basic inventive idea, the peripheral areasin the front part and also in the rear part are advantageously designedin accordance with the invention such that at least threenon-elasticized peripheral sections are provided for each leg opening.

In an advantageous fashion, elasticizing means extending substantiallyin one transverse direction are provided in the crotch area of thehygiene article. Such an elasticizing means in the area of theabsorption body can produce a desired contracting motion of the suctionbody in the crotch area. The absorption body is advantageously narrow inthe crotch area while still providing sufficient absorbing capacity,i.e. absorbent material. The surface density in this area may beincreased through contraction in order to provide a large absorptioncapacity in this area. Moreover, elasticizing means extending in atransverse direction in the crotch area provide the hygiene article withits shape. The crotch area is advantageously cup-shaped.

The elasticizing means extending substantially in the transversedirection in the crotch area or the elasticizing means may be formedseparately from those elasticizing means which elasticise the legopenings. In accordance with a further embodiment of the invention, theelasticizing means of the third peripheral section advantageously mergeinto the elasticizing means of the crotch area, i.e. form theelasticizing means extending in a transverse direction in the crotcharea, in that they merge from their extension in the peripheraldirection of the leg openings substantially in the transverse direction.They may thereby branch off in a substantially steady or unsteady curveprogression, wherein a steady progression is preferred. The fourthnon-elasticized peripheral section may be formed by elasticizing meansextending from the third peripheral section along a curve to the left,and then traversing the crotch area in a transverse direction. Thefourth, non-elasticized peripheral section advantageously covers thecenter crotch line. The center crotch line extends through the minimumwidth of the crotch area of the hygiene article. When the minimum cannotbe uniquely determined, the center crotch line extends through thecenter of the crotch area of the hygiene article. The center of thecrotch area of a hygiene article can be determined by disposing anelastic thread or rubber band in the shape of a figure eight about thelegs of a user standing upright or a user lying prostrate on a flatsupport, such that the thread or band crosses at one point between thelegs. This crossing point is defined as the center of the crotch area ofthe hygiene article during proper use.

The respective non-elasticized second and/or fourth peripheral sectionsmay just not be provided with elasticizing means. Another feasible andadvantageous possibility is that the elasticizing means initiallycontinuously extend in the peripheral direction of the leg openingsduring production of the inventive hygiene article, and thenon-elasticized second and/or fourth peripheral section is/are obtainedby cutting through the previously extended elasticizing means. Theelasticizing means will then relax or retract unless they are connected,e.g. glued to chassis-forming materials in the second and/or fourthperipheral section. This connection of the elasticizing means shouldthen be limited to the first and third peripheral section which issupposed to be elasticized, so that the cut elasticizing means in thesecond peripheral section can relax, thereby losing their elasticizingeffect on the second peripheral section.

The elasticizing means in the second and/or fourth peripheral sectioncan be separated with one single cut. However, it may be feasible andadvantageous to sever the elasticizing means using a plurality of cutssuch that the elasticizing means which previously continuously extendedin the second and/or fourth peripheral section are divided into aplurality of small sections, in particular, of a length in themillimeter range, thereby losing their elasticizing effect on the secondand/or fourth peripheral section. In this case, the elasticizing meansmay also be connected, e.g. glued, to chassis materials in the secondand/or fourth peripheral section without impairing relaxation. Theelasticizing means may be easily cut once or several times using lasertechnology.

In accordance with the invention, the non-elasticized second and/orfourth peripheral section is obtained in that the previously extendingelasticizing means loose their elasticizing effect through applicationof heat and/or pressure and/or laser. This may be achieved, inparticular, through irradiation with ultrasound. It is thereby possibleto deactivate a previously extending pretensioned elasticizing means bydeforming it, in particular, through punctiform or matrix-likeapplication of pressure and/or temperature, in particular, ultrasound,and, in particular, cutting it such that at least its elasticizingeffect on the respective peripheral section is eliminated.

Application of heat and/or pressure is more advantageous than cutting inthat it reduces the danger of chassis-forming materials beinginadvertently cut or perforated. On the other hand, it may beparticularly advantageous to cut or perforate the chassis-formingmaterials in the area of the second and/or fourth peripheral sections,in order to render the hygiene article more breathable at theselocations. In particular, when absorption bodies in the form of afunctional unit having an absorbent structure and a liquid-impermeableback sheet are used directly below the absorbent structure, the otherchassis materials need not be absolutely impermeable to liquids. It mayeven be desirable to only use air-permeable chassis materials in orderto effect breathability. When the above-mentioned functional units areused as an absorption body, chassis materials of non-woven materials ornon-woven laminates may advantageously be used. Non-woven laminates withbreathable or even liquid-permeable sheets are also feasible. Theabove-mentioned functional units used as an absorption body may alsocomprise integrated top sheet layers, and advantageously uprightelasticizing collar elements (so-called “cuffs”) which form a lateraloutlet barrier. Such collar elements may also be provided outside of theabsorption body or the functional unit used as the absorption body.

In accordance with a further inventive idea, a track is advantageouslyprovided which is continuous in the transverse direction for applyingheat and/or pressure and also covers the second and/or fourth peripheralsection of the respective leg opening. This track, which continuouslyextends in the transverse direction, may advantageously be producedthrough continuous, i.e. non-interrupted processing in the machinedirection of the materials forming the hygiene article. This isadvantageous with regard to production.

Reference is made to EP 1 374 814 A1 which discloses a technology ofapplying heat and/or pressure for deactivating elasticizing means, theentire disclosure of which is hereby incorporated by reference.

It has turned out to be suitable and advantageous for the firstelasticizing peripheral section to extend in the peripheral direction ofthe leg openings (best viewed in the “flat state” of the sheet materialsforming the hygiene article) by 3 to 15 cm, in particular 4 to 15 cm, inparticular 5 to 15 cm, and moreover preferentially 5 to 13 cm. The “flatstate” thereby means that the hygiene article is disposed or projectedonto a support such that its chassis materials are no longer gathered bythe elasticizing means. In correspondence with the above-describedposition of this first peripheral section, the hygiene article, beingreadily configured and applied to a user, extends from the side from theapex, facing the hip, of the respective leg opening in the clockwisedirection or in an anticlockwise direction.

The second non-elasticized peripheral section advantageously extends inthe peripheral direction in the flat state by 1 to 10 cm, in particular2 to 8 cm and preferentially 3 to 8 cm.

The third, likewise elasticized peripheral section advantageouslyextends in the peripheral direction in the flat state by 1 to 8 cm, inparticular 1 to 7 cm, and preferentially 1 to 5 cm.

The fourth non-elasticized peripheral section advantageously extends inthe peripheral direction in the flat state by 1 to 7 cm, in particular 1to 5 cm, and preferentially 1 to 4 cm.

Further features, details and advantages of the invention can beextracted from the enclosed claims and the drawing and the followingdescription of a preferred embodiment of the inventive hygiene article.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 shows a top view of a first embodiment of an inventive hygienearticle in the flat state prior to being connected at the longitudinalside edge areas at the manufacturing plant;

FIG. 2 shows a view of a further embodiment of an inventive hygienearticle which corresponds to FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1 shows a hygiene article, designated in total with referencenumeral 2, in the form of a pants-type diaper (“pants”) in the flatstate before being connected at the longitudinal side edge sections atthe manufacturing plant. The hygiene article comprises a rear part 4, afront part 6, and an intermediate crotch part 10 delimiting the futureleg openings 8. In the flat state, the rear part 4 is delimited bylongitudinal side edges 12 and the front part 6 is delimited bylongitudinal side edges 14. These are connected to each other in thearea of the hatched zones 16 and 18 to form the pants shape, i.e.through hot sealing or other conventional joining methods. In thisfashion, two side seam areas of the hygiene article are formed whichcannot be released without causing damage. The readily configuredhygiene article may have a breaking line, e.g. in the form of a releasethread, in particular, along these side seam areas so that the hygienearticle can be opened in the applied state. Additionally, any closingelements, i.e. adhesive or mechanically connecting closure shackles maybe provided so that the hygiene article can be closed again afteropening, like a diaper. The hygiene article is produced by themanufacturer in the form of pants having a hip edge 20 which is closedin the peripheral direction and forms a hip opening which is limited onall sides. It is therefore a pants and not a diaper, which can be openedand closed.

The hygiene article 2 also comprises an absorbent body 22 which may alsobe designed as a functional unit, i.e. may have a liquid absorbingstructure with a liquid-impermeable back sheet and optionally furthercomponents such as e.g. a top sheet and elasticized collar elements, andbe disposed as a functional unit onto chassis-forming materials 24 ofthe hygiene article 2. These chassis-forming materials 24 may e.g. beany back sheet materials or composite materials. Non-woven materials ornon-woven laminates and also non-woven sheet laminates areadvantageously used which have a textile-like surface and are preferablyalso breathable, at least in some areas. The chassis-forming materials24 may also comprise a top sheet layer facing the body, which covers theabsorption body 22 and may extend in a transverse direction 26 and/or ina longitudinal direction 28 of the hygiene article 2 up to the edgesthereof.

FIG. 1 also shows elasticizing means 30 which continuously extend in thetransverse direction 26 and continuously elasticise a hip edge area 32of the hygiene article 2. Elasticizing means 36 are moreover indicatedby dashed lines in the rear part 4 and in the front part 6 at aseparation 34 of 5 to 15 mm from each other, which elasticise onlyregions of the rear part 4 and front part 6 and provide good fit for thehygiene article 2.

Elasticizing means 38 are moreover shown which elasticise sections ofthe leg openings 8 as described below:

The elasticizing means 38 extend from the longitudinal side edge 12 ofthe rear part 4 along a periphery 40 of the respective leg opening 8 inthe direction towards a center crotch line 42. The elasticizing effectof the elasticizing means 38 is not continuous to the center crotch line42 but is limited from the longitudinal side edge 12 to a firstperipheral section 44 of the leg openings 8. A second non-elasticizedperipheral section 46 of the leg openings is adjacent thereto, to whichan elasticized third peripheral section 48 is adjacent. This thirdperipheral section 49 is joined by a fourth non-elasticized peripheralsection, which extends over the center crotch line 42. The periphery 40of the leg openings 8 is therefore not continuously elasticized. It isnot elasticized in the rear part 4 and/or front part 6 in respectivesecond peripheral sections 46 and in a fourth peripheral section 49.This means that the chassis materials 24 in these second and fourthperipheral sections 46 and 49 are not disposed against the skin surfaceof the user by elastically pretensioning the mostly thread-shapedelasticizing means 38, rather softly abut the skin surface. Thisimproves the breathability, i.e. improves ventilation of the areasoutside of the absorption body 22, as is indicated by arrow 50.Moreover, the chassis materials 24 are not gathered or frilled in thesecond and fourth peripheral sections 46 and 49, which increases theskin friendliness, since skin irritation is reduced.

The second peripheral section 46 of FIG. 1 does not have anyelasticizing means 38. This may advantageously be achieved in that theelasticizing means 38 initially continuously extend through all threeperipheral sections but are connected, preferably glued, to the chassismaterials 24 only in the first and third peripheral section 44, 48 inthe pretensioned state. The elasticizing means 38 must be merely cut inthe second peripheral section 46, and retract due to their pretension,to their fixture in the first and third peripheral sections 44, 48, suchthat the second peripheral section 46 is no longer elasticized. Thefourth peripheral section 49 is thereby not elasticized, such that theelasticizing means 38 extend from their extension in the thirdperipheral section 46 along a curve to the inside in the transversedirection 26. The fourth peripheral section 49 is thereby formed betweenthe respective third peripheral section 46 of the rear part 4 and thefront part 6.

The elasticizing means 38 in the second peripheral section 46 of thefront part 6 are shown with dotted lines on the left hand side ofFIG. 1. This represents a further embodiment of the invention, in whichthe elasticizing means 38, which previously continuously extended fromthe longitudinal side edge 14 to the center crotch line 42, were cutseveral times in the second peripheral section 46 at a separation of 1to 3 mm. In this fashion, the elasticizing means 38 in the secondperipheral section 46 are deactivated. Cutting the elasticizing means 38several times can be achieved by a knife roller in a production machinewhich rolls over the sheet materials transported in the machinedirection in the transverse direction 26. In this case, the previouslycontinuously disposed elasticizing means 38 could also be connected,i.e. glued to the chassis materials 24 in the second peripheral section46, if this seems to be suitable or is desired for production.

In accordance with a further preferred embodiment of the invention whichmay also be indicated by the dashed lines in the front part 6 in FIG. 1on the left hand side, the elasticizing means 38 previously continuouslyextending from a longitudinal side edge to the center crotch line 42have lost their elasticizing effect in the second peripheral section 46through application of heat and/or pressure. The elasticizing means 38may be deactivated or relaxed through application of heat and/orpressure, i.e. through ultrasound welding methods or through a matrix ofheating which results in melting. They are thereby substantiallydestroyed and can no longer elasticise the second peripheral section 46.

Moreover, elastification extending in the transverse direction 26 isprovided in the area of the center crotch line 42. This isadvantageously achieved, as mentioned above, in that the above-mentionedelasticizing means 38 “bend” inwards from their extension in theperipheral direction in the third peripheral section 48, i.e. aredeflected in the transverse direction 26, and traverse the crotch area10 in the transverse direction 26 below the absorption body 22, i.e.between the absorption body 22 and the chassis materials 24, to thenfurther extend steadily and continuously into the periphery of theopposite leg opening 8. This guidance of the elasticizing means 38starting from the third peripheral section 46 is separately claimed andis regarded as an independent invention, i.e. independently of thefurther features of the claims. Departing from the above-describedmethods for relaxing the elasticizing means 28 in the second peripheralsection 46, it is possible to continuously guide the elasticizing means38 in the machine direction which corresponds to the transversedirection 26, and to join them to the chassis materials 24 of thehygiene article. This is considered to be particularly advantageous.

Finally, reference is made to the collar elements 52 (“cuffs”) providedon both sides of the absorption body 22, which are elasticized andtherefore upright, and which form a lateral barrier for leaking bodyexcretions and also retain liquid body excretions in the area above theabsorption body until they have been absorbed by the absorption body 22.

FIG. 2 shows a further embodiment, wherein the elasticizing means 38′traverse the crotch area but are subsequently deactivated in aconventional fashion, i.e. they are cut or rendered non-elasticizing ina different fashion, in particular through application of heat and/orpressure as mentioned above.

1. A method for manufacturing a pants-shaped disposable absorbenthygiene article having a longitudinal direction and a transversedirection and a chassis comprising front and rear right edges and frontand rear left edges attached to each other, the method comprising thesteps of: a) preparing and transporting flat chassis-forming sheetmaterials in a transport direction parallel to the transverse directionof the article such that the front and rear right edges lead and thefront and rear left edges trail; b) preparing the chassis in a flatform, the chassis having a front part, a rear part spaced apart from thefront part in a longitudinal direction of the article and a crotch partdisposed between and contiguous with the front part and the rear part,the crotch part defining a center crotch line extending in thetransverse direction of the article, the rear part having a rear rightedge and a rear left edge spaced apart from the rear right edge in thetransverse direction of the article, the front part having a front rightedge and a front left edge spaced apart from the front right edge in thetransverse direction; c) applying a continuous first thread-shapedelastic means to the flat chassis-forming sheet materials, the firstelastic means extending from an end of the rear right edge to a firstcurve location disposed at a separation from but proximate to the centercrotch line, the first elastic means curving at the first curve locationto proceed in the transverse direction, substantially parallel to thecenter crotch line, the first elastic means curving away from the centercrotch line at a second curve location to travel to an end of the rearleft edge; d) applying a continuous second thread-shaped elastic meansto the flat chassis-forming sheet materials, the second elastic meansextending from an end of the front right edge to a third curve locationat a separation from but proximate to the center crotch line, the secondelastic means curving at the third curve location to proceed in thetransverse direction, substantially parallel to the center crotch line,the second elastic means curving away from the center crotch line at afourth curve location to travel up to an end of the front left edge; e)removing, following step c), an elasticity of a first right and a secondleft portion of the first elastic means by cutting or throughapplication of heat, pressure and/or laser, the first right portion ofthe first elastic means disposed proximate the crotch center linebetween the first curve location and the end of the rear right edge, thesecond left portion of the first elastic means disposed proximate thecrotch center line between the second curve location and the end of therear left edge; f) removing, following step d), an elasticity of a thirdright and a fourth left portion of the second elastic means by cuttingor through application of heat, pressure and/or laser, the third rightportion of the second elastic means disposed proximate the crotch centerline between the third curve location and the end of the front rightedge, the fourth left portion of the second elastic means disposedproximate the crotch center line between the fourth curve location andthe end of the front left edge; g) disposing an absorbent body onto thechassis-forming sheet materials; h) removing material from thechassis-forming sheet materials to define leg openings in the crotchpart, the crotch part thereby having a crotch right edge defining afirst leg opening for a user, the crotch right edge extending in thelongitudinal and transverse directions in a curved, inwardly taperedmanner away from the end of the rear right edge outside of, proximate,and substantially parallel to a travel of the first elastic meansupstream of the first curve location, the crotch right edge continuingpast the first curve location, the center crotch line, and the thirdcurve location to curve outwardly in transverse and longitudinal traveloutside of, proximate and substantially parallel to a travel of thesecond elastic means downstream of the third curve location andterminating at the end of the front right edge, the crotch part having acrotch left edge defining a second leg opening for the user, the crotchleft edge extending in the longitudinal and transverse directions in acurved, inwardly tapered manner away from the end of the rear left edgeoutside of, proximate, and substantially parallel to a travel of thefirst elastic means upstream of the second curve location, the crotchleft edge continuing past the second curve location, the center crotchline, and the fourth curve location to curve outwardly in transverse andlongitudinal travel outside of, proximate and substantially parallel toa travel of the second elastic means downstream of the fourth curvelocation and terminate at the end of the front left edge, wherein thecrotch part thereby exhibits a narrowed, tapered transverse width at thecenter crotch line; and i) attaching the rear right edge to the frontright edge and the rear left edge to the front left edge of the chassisthereby forming the pants-shaped disposable absorbent hygiene article.2. The method of claim 1, wherein step g) precedes step i).
 3. Themethod of claim 1, wherein at least one of steps e) and f) comprisesapplication of a plurality of cuts to at least one of the first, second,third and fourth portions.
 4. The method of claim 1, wherein at leastone of the first, second, third and fourth portions have macroscopicventilation openings in chassis-forming materials thereof.
 5. The methodof claim 1, wherein the absorbent body comprises a functional unit withan absorbent structure and a liquid-impermeable back sheet which isconnected to the chassis.
 6. The method of claim 1, wherein the chassisconsists essentially of a non-woven material or a non-woven laminate. 7.The method of claim 1, wherein the first elastic means extends betweenthe end of the rear right edge to a beginning of the first portionthrough a length of 3 to 15 cm, 4 to 15 cm, 5 to 15 cm, or 5 to 13 cm.8. The method of claim 7, wherein the first portion extends through alength of 1 to 10 cm, 2 to 8 cm, or 3 to 8 cm.
 9. A pants-shapeddisposable absorbent hygiene article produced by the method of claim 1.